[0.14.7] Multiplayer autocomplete with Tab

[kappa]

Hi, I just run into a tiny bug:

Problem:
When you try to complete name with tab key in a command prompt, the algorithm does is not completing the word you are currently typing, instead it finds the first occurance of the currently typed prefix and inserts the predicted suffix there.

How to reproduce:
For example:
We've got kappa connected to the game, we start typing "kappa kap", then we hit <tab>, which should result in "kappa kappa" but instead it will result in "kappapa kap"

Solution:
The solution would be to simply add the predicted suffix to the end of the command, since you can not tab-complete any other word but the last one.

System:
Currently on version 0.14.7, running from Steam on Ubuntu 16.04.

[Rseding91]

Fixed for 0.14.8.